Can confirm that mine is red aswell when the dash light are turned on. But it can be pretty much anything. I would suggest you check your brand and then go to the manufacturers homepage or whatever and ask there. Or did you already figure it out?

Red is the preferred color because you would typically only need the light on at night. if you're running at night, you want to preserve your night vision. Red allows you to maintain night vision. All my gauge lights and switch lights are red from the factory. I assumed they all were. I run at night often. I would hate white lights on my gauges.

When I bought my compass the boxes had stickers on them indicating the light color. It said red. I installed it the day and couldn't tell if the the light was working in the bright sunlight. I quickly forgot about it. Then one night I turned on my dash lights. It was green!! WTF??!!!

I never bothered uninstalling it and returning it. I've seen some boats with amber lights as well as blue lights.